GtkSharp/gtk/TreeModelFilter.custom

		[DllImport ("libgtk-win32-3.0-0.dll", CallingConvention = CallingConvention.Cdecl)]
		static extern bool gtk_tree_model_iter_children (IntPtr raw, out Gtk.TreeIter iter, IntPtr parent);
		public bool IterChildren (out Gtk.TreeIter iter) {
			bool raw_ret = gtk_tree_model_iter_children (Handle, out iter, IntPtr.Zero);
			bool ret = raw_ret;
			return ret;
		}

		public int IterNChildren () {
			int raw_ret = gtk_tree_model_iter_n_children (Handle, IntPtr.Zero);
			int ret = raw_ret;
			return ret;
		}

		[DllImport ("libgtk-win32-3.0-0.dll", CallingConvention = CallingConvention.Cdecl)]
		static extern bool gtk_tree_model_iter_nth_child (IntPtr raw, out Gtk.TreeIter iter, IntPtr parent, int n);
		public bool IterNthChild (out Gtk.TreeIter iter, int n) {
			bool raw_ret = gtk_tree_model_iter_nth_child (Handle, out iter, IntPtr.Zero, n);
			bool ret = raw_ret;
			return ret;
		}

		public void SetValue (Gtk.TreeIter iter, int column, bool value) {
			throw new NotImplementedException ();
		}

		public void SetValue (Gtk.TreeIter iter, int column, double value) {
			throw new NotImplementedException ();
		}

		public void SetValue (Gtk.TreeIter iter, int column, int value) {
			throw new NotImplementedException ();
		}

		public void SetValue (Gtk.TreeIter iter, int column, string value) {
			throw new NotImplementedException ();
		}

		public void SetValue (Gtk.TreeIter iter, int column, float value) {
			throw new NotImplementedException ();
		}

		public void SetValue (Gtk.TreeIter iter, int column, uint value) {
			throw new NotImplementedException ();
		}
		
		public void SetValue (Gtk.TreeIter iter, int column, object value) {
			throw new NotImplementedException ();
		}

		public object GetValue (Gtk.TreeIter iter, int column) {
			GLib.Value val = GLib.Value.Empty;
			GetValue (iter, column, ref val);
			object ret = val.Val;
			val.Dispose ();
			return ret;
		}

		[DllImport ("libgtk-win32-3.0-0.dll", CallingConvention = CallingConvention.Cdecl)]
		static extern void gtk_tree_model_filter_set_modify_func(IntPtr raw, int n_columns, IntPtr[] types, GtkSharp.TreeModelFilterModifyFuncNative func, IntPtr data, GLib.DestroyNotify destroy);

		public void SetModifyFunc (int n_columns, GLib.GType[] types, TreeModelFilterModifyFunc func) 
		{
			GtkSharp.TreeModelFilterModifyFuncWrapper func_wrapper = new GtkSharp.TreeModelFilterModifyFuncWrapper (func);
			IntPtr[] native_types = new IntPtr [types.Length];
			for (int i = 0; i < types.Length; i++)
				native_types [i] = types [i].Val;
			GCHandle gch = GCHandle.Alloc (func_wrapper);
			gtk_tree_model_filter_set_modify_func (Handle, n_columns, native_types, func_wrapper.NativeDelegate, (IntPtr) gch, GLib.DestroyHelper.NotifyHandler);
		}

		[DllImport ("libgtk-win32-3.0-0.dll", CallingConvention = CallingConvention.Cdecl)]
		static extern bool gtk_tree_model_filter_convert_child_iter_to_iter (IntPtr raw, out Gtk.TreeIter filter_iter, ref Gtk.TreeIter child_iter);

		public TreeIter ConvertChildIterToIter (Gtk.TreeIter child_iter)
		{
			TreeIter filter_iter;
			if (gtk_tree_model_filter_convert_child_iter_to_iter(Handle, out filter_iter, ref child_iter))
				return filter_iter;
			else
				return TreeIter.Zero;
		}

		[UnmanagedFunctionPointer (CallingConvention.Cdecl)]
		delegate void RowsReorderedSignalDelegate (IntPtr arg0, IntPtr arg1, IntPtr arg2, IntPtr arg3, IntPtr gch);

		static void RowsReorderedSignalCallback (IntPtr arg0, IntPtr arg1, IntPtr arg2, IntPtr arg3, IntPtr gch)
		{
			Gtk.RowsReorderedArgs args = new Gtk.RowsReorderedArgs ();
			try {
				GLib.Signal sig = ((GCHandle) gch).Target as GLib.Signal;
				if (sig == null)
					throw new Exception("Unknown signal GC handle received " + gch);

				TreeModelFilter sender = GLib.Object.GetObject (arg0) as TreeModelFilter;
				args.Args = new object[3];
				args.Args[0] = arg1 == IntPtr.Zero ? null : (Gtk.TreePath) GLib.Opaque.GetOpaque (arg1, typeof (Gtk.TreePath), false);
				args.Args[1] = Gtk.TreeIter.New (arg2);
				int child_cnt = arg2 == IntPtr.Zero ? sender.IterNChildren () : sender.IterNChildren ((TreeIter)args.Args[1]);
				int[] new_order = new int [child_cnt];
				Marshal.Copy (arg3, new_order, 0, child_cnt);
				args.Args[2] = new_order;
				Gtk.RowsReorderedHandler handler = (Gtk.RowsReorderedHandler) sig.Handler;
				handler (sender, args);
			} catch (Exception e) {
				GLib.ExceptionManager.RaiseUnhandledException (e, false);
			}
		}

		[UnmanagedFunctionPointer (CallingConvention.Cdecl)]
		delegate void RowsReorderedVMDelegate (IntPtr tree_model, IntPtr path, IntPtr iter, IntPtr new_order);

		static RowsReorderedVMDelegate RowsReorderedVMCallback;

		static void rowsreordered_cb (IntPtr tree_model, IntPtr path_ptr, IntPtr iter_ptr, IntPtr new_order)
		{
			try {
				TreeModelFilter store = GLib.Object.GetObject (tree_model, false) as TreeModelFilter;
				TreePath path = GLib.Opaque.GetOpaque (path_ptr, typeof (TreePath), false) as TreePath;
				TreeIter iter = TreeIter.New (iter_ptr);
				int child_cnt = store.IterNChildren (iter);
				int[] child_order = new int [child_cnt];
				Marshal.Copy (new_order, child_order, 0, child_cnt);
				store.OnRowsReordered (path, iter, child_order);
			} catch (Exception e) {
				GLib.ExceptionManager.RaiseUnhandledException (e, true);
				// NOTREACHED: above call doesn't return
				throw e;
			}
		}

		private static void OverrideRowsReordered (GLib.GType gtype)
		{
			if (RowsReorderedVMCallback == null)
				RowsReorderedVMCallback = new RowsReorderedVMDelegate (rowsreordered_cb);
			OverrideVirtualMethod (gtype, "rows_reordered", RowsReorderedVMCallback);
		}

		[Obsolete ("Replaced by int[] new_order overload.")]
		[GLib.DefaultSignalHandler(Type=typeof(Gtk.TreeModelFilter), ConnectionMethod="OverrideRowsReordered")]
		protected virtual void OnRowsReordered (Gtk.TreePath path, Gtk.TreeIter iter, out int new_order)
		{
			new_order = -1;
		}

		[GLib.DefaultSignalHandler(Type=typeof(Gtk.TreeModelFilter), ConnectionMethod="OverrideRowsReordered")]
		protected virtual void OnRowsReordered (Gtk.TreePath path, Gtk.TreeIter iter, int[] new_order)
		{
			int dummy;
			OnRowsReordered (path, iter, out dummy);
			GLib.Value ret = GLib.Value.Empty;
			GLib.ValueArray inst_and_params = new GLib.ValueArray (4);
			GLib.Value[] vals = new GLib.Value [4];
			vals [0] = new GLib.Value (this);
			inst_and_params.Append (vals [0]);
			vals [1] = new GLib.Value (path);
			inst_and_params.Append (vals [1]);
			vals [2] = new GLib.Value (iter);
			inst_and_params.Append (vals [2]);
			int cnt = IterNChildren (iter);
			IntPtr new_order_ptr = Marshal.AllocHGlobal (Marshal.SizeOf (typeof (int)) * cnt);
			Marshal.Copy (new_order, 0, new_order_ptr, cnt);
			vals [3] = new GLib.Value (new_order_ptr);
			inst_and_params.Append (vals [3]);
			g_signal_chain_from_overridden (inst_and_params.ArrayPtr, ref ret);
			Marshal.FreeHGlobal (new_order_ptr);

			foreach (GLib.Value v in vals)
				v.Dispose ();
		}

		[GLib.Signal("rows_reordered")]
		public event Gtk.RowsReorderedHandler RowsReordered {
			add {
				GLib.Signal sig = GLib.Signal.Lookup (this, "rows_reordered", new RowsReorderedSignalDelegate(RowsReorderedSignalCallback));
				sig.AddDelegate (value);
			}
			remove {
				GLib.Signal sig = GLib.Signal.Lookup (this, "rows_reordered", new RowsReorderedSignalDelegate(RowsReorderedSignalCallback));
				sig.RemoveDelegate (value);
			}
		}